The bleomycins (BLMs) are a family of glycopeptide-derived antitumor antibiotics used clinically for the treatment of squamous cell carcinomas and malignant lymphomas. [Levi, J. A. et al., J. Clin. Oncol. 1993, 11, 1300; Bleomycin Chemotherapy; Sikic, B. I., Rozencweig, M., Carter, S. K., Eds.; Academic Press: Orlando, Fla., 1985.] Their antitumor activity is thought to result from selective oxidative cleavage of 5′-GC-3′ and 5′-GT-3′ sequences in DNA and possibly also from oxidative degradation of RNA. [Holmes, C. E. et al., Biochemistry 1993, 32, 4293; Kane. S. A.; Hecht. S. M. Prog. Nucleic Acid Res. Mol. Biol. 1994, 49, 313; Claussen, C. A.; Long, E. C. Chem. Rev. 1999, 99, 2797; Hecht, S. M. J. Nat. Prod. 2000, 63, 158; Abraham, A. T. et al., Chem. Biol. 2003, 10, 45; Chen, J.; Stubbe, J. Nat. Rev. Cancer 2005, 5, 102; Tao, Z. F.; Konishi, K. et al., J. Am. Chem. Soc. 2006, 128, 14806]. In addition to its antitumor activity, BLM has been recognized for its ability to target tumors and shown to act as a tumor-imaging agent. [Jones, S. E.; Lilien, D. L.; O'Mara, R. E.; Durie, B. G.; Salmon, S. E. Med. Pediatr. Oncol. 1975, 1, 11; Silverstein, M. J.; Verma, R. C.; Greenfield, L.; Morton, D. L. Cancer 1976, 37, 36; Bekerman, C.; Moran, E. M.; Hoffer, P. B.; Hendrix, R. W.; Gottschalk. A. Radiology 1977, 123, 687; Burton, I. E.; Todd, J. H.; Turner, R. L. Br. J. Radiol. 1977, 50, 508; Goodwin, D. A.; Meares. C. F.; DeRiemer, L. H.; Diamanti, C. I.; Goode, R. L.; Baumert, J. E., Jr.; Sartoris, D. J.; Lantieri, R. L.; Fawcett. H. D. J. Nucl. Med. 1981, 22, 787; Stem, P. H.; Helpern, S. E.; Hagan, P. L.; Howell, S. B.; Dabbs, J. E.; Gordon, R. M. J, Natl. Cancer Inst. 1981, 66, 807].